Aquaporin-4 antibody negative recurrent isolated optic neuritis: Clinical evidence for disease heterogeneity

We studied a series of 10 patients who presented with recurrent episodes of isolated optic neuritis (ON, n = 57) and were followed over a median of 3.5 years. Visual acuity was severely reduced at the nadir of the disease (20/200 to 20/800). All patients had MRI non-diagnostic for MS/NMO and were aquaporin-4 antibody negative. Six patients fulfilled the CRION criteria. In two of these a single ON followed by a long disease-free interval preceded development of CRION for years, suggesting the conversion of an initially “benign” isolated ON into the chronic relapsing course. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis in 5 patients, identical oligoclonal bands in serum and CSF were observed in 2 patients, while the others remained negative. In conclusion, recurrent ON is a disease entity that requires aggressive glucocorticoid and eventually long-term immunosuppressive therapy to prevent substantial visual impairment.